scholarly journals Recovery of Residues from Olive Industry: Characterization of Simple and Acetylated Lignin

2020 ◽  
Vol 44 (5) ◽  
pp. 327-332
Author(s):  
Amine Abid ◽  
Fatima Charrier El Bouhtoury ◽  
Slimane Gabsi
Keyword(s):  
Mass Distribution ◽  
Molar Mass ◽  
High Molar Mass ◽  
Process Comparison ◽  
H Nmr ◽  
Organosolv Lignin ◽  
Renewable Material ◽  
Olive Residue ◽  
Olive Industry

Lignin is a renewable material obtained in large quantities as a by-product of the olive industry. In this context, this study aims to examine lignin as macro-monomers in the synthesis of rigid polyurethane foam after chemical modification. Indeed, the lignin extracted from the olive residue is used by chemical treatment according to the organosolv process. Comparison by characterization of the single isolated lignin and the acetylated lignin according to the physicochemical analysisTGA, DSC, FTIR, C-13 NMR, 1-H NMR, and molar mass distribution (sec) shows its value as biomass capable of being transformed into polyol afterchemical modification. acetylation increases the weight and the number of molar masses by 25-50% was also determined. Acetylation has a greater effect on the short chains which are probably richer in free phenolic groups. Mass distribution analyzes reveal a relatively high molar mass in organosolv lignin moreover, polydispersity values are very high (20 >> 1). The characterization of spent olive cake reflects the interest of using this biomass as a source of renewable energy for the production of industrial polymers.

scholarly journals Molar mass determination of lignins and characterization of their polymeric structures by multi-detector gel permeation chromatography

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Evamaria C. Gaugler ◽  
Wolfgang Radke ◽  
Andrew P. Vogt ◽  
Dawn A. Smith
Keyword(s):  
Molar Mass ◽  
Lithium Bromide ◽  
Gel Permeation Chromatography ◽  
Mass Determination ◽  
Organosolv Lignin ◽  
Gel Permeation ◽  
Softwood Kraft Lignin ◽  
Polymeric Structures

AbstractMolar masses, Mark-Houwink-Sakurada (MHS) exponents, and refractive index increments (dn/dc) for three lignins were determined without derivatization by multi-detector gel permeation chromatography (GPC) in dimethylformamide (DMF) with 0.05 M lithium bromide (LiBr). The lack of effectiveness of fluorescence filters on molar mass determination by GPC-multi-angle laser light scattering (MALS) was confirmed for softwood kraft lignin (Indulin AT) and revealed for mixed hardwood organosolv lignin (Alcell) as well as soda straw/grass lignin (Protobind 1000). GPC with viscometry detection confirmed that these lignins were present as compact molecules. The MHS exponent α for Indulin AT and Alcell was in the order of 0.1. Additionally, the intrinsic viscosity of Protobind 1000 for a given molar mass was much lower than that of either Alcell or Indulin AT. This is the first report of dn/dc values for these three lignins in DMF with 0.05 M LiBr.

Molecular weight and contraction factors of hyperbranched poly(urea-urethane)s

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Albena Lederer ◽  
Mona Abd Elrehim ◽  
Falko Schallausky ◽  
Dieter Voigt ◽  
Brigitte Voit
Keyword(s):  
Chemical Structure ◽  
Molar Mass ◽  
Molecular Shape ◽  
Branched Polymers ◽  
Compact Structure ◽  
H Nmr ◽  
Hyperbranched Poly ◽  
End Groups ◽  
Solution Behaviour

AbstractElution fractionations of broadly molar mass-distributed, hyperbranched poly(urea-urethane)s with OH- and Ph- end groups were carried out to obtain a number of macromolecular samples possessing different molar masses at the same chemical structure. The characterization of the polymers was performed by SEC, MALLS, 1H-NMR, MALDI-TOF-MS and viscosity measurements. Modifications of the OH-end groups of the polymers were carried out. We observed a strong influence of the end groups on the solution behaviour of the hyperbranched samples. The molecular shape of the hyperbranched polymers in solution was compared to their linear analogue using the Kuhn-Mark-Houwink- Sakurada relationship. The calculated contraction factors between 0,15 and 0,7 depending on the molar masses correspond to a very compact structure of the modified branched polymers at high molar masses.

Characterization of Chemical Composition along the Molar Mass Distribution in Polyolefin Copolymers by GPC Using a Modern Filter-Based IR Detector

2013 ◽  
Vol 330 (1) ◽  
pp. 63-80 ◽  
Author(s):  
A. Ortín ◽  
J. Montesinos ◽  
E. López ◽  
P. del Hierro ◽  
B. Monrabal ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Mass Distribution ◽  
Molar Mass ◽  
Molar Mass Distribution ◽  
Ir Detector

Composition and molar mass characterisation of bacterial extracellular polymeric substances by using chemical, spectroscopic and fractionation techniques

2011 ◽  
Vol 8 (2) ◽  
pp. 155 ◽  
Author(s):  
Enrica Alasonati ◽  
Vera I. Slaveykova
Keyword(s):  
Chemical Composition ◽  
Mass Distribution ◽  
Sinorhizobium Meliloti ◽  
Extracellular Polymeric Substances ◽  
Molar Mass ◽  
Waste Water Treatment ◽  
Molar Mass Distribution ◽  
Spectroscopic Techniques ◽  
High Molar Mass ◽  
Vis Spectroscopy

Environmental contextExtracellular polymeric substances (EPS) released by microorganisms are an important component of organic matter in the environment. EPS play an essential role in cell adhesion to surfaces, biofilm and floc formation, soil aggregation and stability and in the activated sludge of waste water treatment plants. EPS are complex mixtures containing components of different chemical nature and molecular size, which make their characterisation difficult. The present work explores the link between chemical composition and molar-mass distribution of the EPS released by the bacterium Sinorhizobium meliloti by using a combination of chemical, spectroscopic and fractionation techniques. AbstractThe chemical composition and molar-mass distribution of extracellular polymeric substances (EPS) produced by the bacterium Sinorhizobium meliloti have been characterised by combining asymmetrical flow field-flow fractionation (AFlFFF), chemical and spectroscopic techniques. The relationship between the EPS composition and molar-mass distribution has been studied by comparing the characteristics of EPS excreted by the wild type S. meliloti and by a mutant deficient in the production of high-molar-mass EPS, as well as by the analysis of total protein content in the collected AFlFFF fractions. Total organic carbon, protein and polysaccharide contents of the EPS were also determined. Obtained results demonstrate the existence of two major populations with weight-average molar masses of 1.40 × 105 and 4.57 × 105 g mol–1 respectively. The lower molar-mass population contained predominantly protein-like substances, detectable by UV-VIS spectroscopy, whereas the higher molar-mass population was rich in exopolysaccharides and exoproteins. These findings are in general agreement with the size distributions and chemical heterogeneity observed by nanoparticle tracking analysis, and the characterisation of the composition of all the EPS by different analytical techniques.

Sign in / Sign up

Export Citation Format

Share Document